RDTN.org: crowdsourcing and mapping radiation levels


One issue that has emerged during the nuclear crisis in Japan is that there isn't always a reliable source for radiation levels from specific areas. RDTN.org has just launched, an experiment to help address that need. The site allows people to submit their own reads, and maps them out next to data from official sources and measurement dates. This way, anyone can quickly get an idea of what is happening on the ground, first-hand. The site is brand new but should be very useful going forward.

Also worth noting and specific to what is going on in Japan right now, JapanStatus.org is "a dashboard of accurate, sourced information on the situation in Japan following the March 2011 disaster."


  1. What has been disturbing to me is the blackout on radiation readings in the most effected areas, it doesn’t seem like even the international nuclear agencies are getting specific data from the Japanese agencies controlling the monitors around the reactors.

    1. If the information is being suppressed in the US or not I have no idea. But whatever organisation would be doing this won’t be doing it in Japan – unless you mean the Illuminati at which point I’ll point out that the Illuminati’s deepest secret is the Mayan calendar and now I’ll be killed for revealing it.

      1. Right, right… industry has never been know to suppress information. Only people who wear tin-foil hats believe such things. Carry on… carry on…

        1. TEPCO has a history of telling porky pies. Here’s a nugget you’ll like – they were hauled over the coals a few years ago for letting workers at one of their plants pre heat fuels rods in a metal bucket on an electric cooker. But given that articles written about that aren’t easily findable by non Japanese speakers it’s not being recycled by the foreign media. Then there are the incidents.

          So nobody in Japan trusted them even prior to this.

          Furthermore the emergency services are livid at TEPCO for expecting them to clean up their mess – hence the police are looking to see if they can get a prosecution for criminal negligence atm.

          They have royally pissed off the Japanese government and its people and the huge corporations.

          To have a cover up you would need collusion of at least one of these groups.

  2. Why is there such a huge difference in the readings between the two sites?
    Japanstatus.org shows an average value of ~50 nSV/h = 0.00005 mSV/h
    RDTN.org shows an average of ~300 uSV/h = 0.3 mSV/h

    Thats a massive difference!
    Is it that Japanstatus.org is information provided by the government?

  3. The photo, as well as the real website, has a serious problem.

    Look at the example photo above; 196 Gy/hr. LD100 (lethal dose for 100% of the population despite heroic medical measures) is 8 Sv. A field of 196 Gy/hr would kill everyone in it within 2.4 minutes.

    Perhaps the RDTN.ORG folks should make the field strength appear in nGy/hr? That would correlate with the estimated absorbed dose of 0.196 mSv/hr.

    DO. THE. MATH.

  4. So, we’re all supposed to trust anyone who says that they have an accurate, recently validated geiger counter? Or no, that isn’t even true it’s just anyone who says that they have a geiger counter without any validation that the values posted are correct. What is there to stop anyone with a badly out of spec geiger counter or someone with an anti-nuke bent from posting high values to panic people? Nothing.

    1. As an anti-nuke peacenik, I can tell you that my #1 preferred method is to spread mass panic. That’s what we’re all about.

    2. So, we’re all supposed to trust anyone who says that they have an accurate, recently validated geiger counter?


      You aggregate data (hence the crowdsourcing moniker in the title).

      What do you prefer as a source? Just one source? And, who do you trust to be that ONE source?

  5. It’s like Wikipedia…most people are honest, and most Geiger counters are likely well-calibrated. So if you see a high reading among a bunch of lower readings, throw out the outlier. It’s either fake, out of calibration, or sitting near a granite tabletop. Same for very low readings. But if 10 readings in one city are nearly the same, they’re probably close to reality.

  6. In the “Where are the Clouds ?” blog ( http://where-are-the-clouds.blogspot.com/ ), we have tried to do something similar except we are interested in not just measurements but also in the plume simulations that are also undertaken by a number of institutes, safety agencies and researchers. The idea is to aggregate both the data from either government and user provided sensor networks and the different simulations (trying) to predict the diffusion of the plumes.

    The blog is not just interested in the Fukushima accident. last year, the ash cloud was also a concern of transnational interest.

  7. Crowdsourcing seems to have failed for the U.S.. The mainstream news reports give us no actual data about the radiation levels here, saying only that the levels are “miniscule” or “thousands of times below the levels of concern”.

    I keep hearing about radiationnetwork.com but a few days ago they had only 3-4 monitoring sites on the west coast and today they are down to 1. A few days ago their west coast sites were showing readings of an average of about 30 cpm and today the 1 remaining site was down to 18 cpm this morning.

    This is the best we can do?

  8. From the above ground nuclear testing, fallout was spread world wide that caused radioactive strontium 90 to occur in milk. Keeping track of a change in that number is important but who is doing it?

    1. @#20 The words “Under Survey” have appeared in place of actual readings for several days on that site. IMCO, that indicates that the readings are too big for the columns, which are in the hundreds of thousands of nGys.

  9. It could also mean the stations are offline.

    It is more interesting to look at those prefectures south of Fukushima now. Wind is coming from northeast towards Tokyo now and one reading in Ibaraki prefecture was briefly reported as 2900nGy/hr. The rain will wash most of that out of the air where it contaminates the soil. *sigh*

  10. It is an landmark event in the history of Japan. The radiations are spreading all over the world and affecting people badly. it’s strange but it doesn’t seem like international nuclear agencies are controlling the monitors around reactors.

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